During a research, the amount of Internet users was measured. Each time three random groups of10,000 people of the average age of 20, 40r and 60 were considered. The data are as follows (xl the number of years since the beginning of the research, x2 - age, y number of users]: 5830 1420 x2 20 40 60 20 40 60 20 40 60 20 40 60 {a} Fit a multiple linear regression model using x. and x2 as the regressors. Round your answers to one decimal place leg. 98.7}. .2: +H mu (b) Estimate oz. Round your answer to the nearest integer (e.g. 9876). {c} Find the standard errors of the regression coefcients. Round your answers to one decimal place (eg. 98.7). sewn) = a new n ...(;.~.) = n (d) Use the model to predict the number of users in random group of 40 years after 4 years of research. Round your answer to the nearest integer (e.g. 9876). Number of users=